The number of households receiving cable or satellite subscriber services continues to increase year to year. This trend is expected to continue, especially with the recent advent of digital television. Digital television systems enable two-way and advanced one-way communications between the subscriber and the system headend. As a consequence, interactive services such as e-mail, interactive programming guides, advanced configuration controls, impulse pay-per-view, video-on-demand, e-commerce, and web browsing may be provided to subscribers of a digital television system. In addition to the interactive services, the increased bandwidth available through a digital television system has made it possible for the subscriber to have access to hundreds, or even thousands, of channels and/or services. Further, the increased bandwidth enables services such as virtual or text channels to become more complex as they may be enhanced by graphical images, audio, and other multimedia content. New multimedia services such as Emergency Alert System (EAS) notifications, e-mail, messaging from operator-to-user or user-to-user also become possible.
While advancements in certain technologies have expanded the complexity and type of services that can be provided over cable and satellite systems, there are still constraints within these systems that may limit the utilization of these emerging technologies. For instance, the non-functional requirements regarding performance and memory consumption are generally viewed as limiting factors in the design and implementation of new services which take advantage of these new technological advancements.
For example, a set-top box, also referred to as a home communication terminal (HCT), is located at a user site for connecting to and interfacing with a subscriber television system, such as a cable or satellite system. For purposes of the present disclosure, set-top boxes, HCT's and other similar devices are collectively referred to herein as communication terminals. Most communication terminals are typically designed to meet the minimum specifications for providing a certain level of functionality. Some of the more common limitations are the amount of volatile memory (e.g., random access memory), the amount of non-volatile memory (e.g., NVRAM and the hard disk), and the performance of the processor (e.g., the processor clock speed and design). These limitations are generally governed by the per unit cost of a communication terminal which is preferably kept low in order to be as competitive as possible. Thus, it is desirable to conserve and reuse certain functionality whenever practical within the architecture of the cable or satellite system, and in particular, at the communication terminal.
In addition, the development of new services is costly, and therefore, the sharing of functionality between services that are executed at the communication terminal and/or the headend may not only reduce the associated overhead in terms of memory, processor time and bandwidth, but may reduce the software development cost as well. Yet further, the management of the user interface at the communication terminal has generally become much more complex as multiple program services compete for presentation to the user.
Many of the new multimedia services, as well as existing services, provide for messaging, such as text presented by a virtual or text channel, a tuned channel, or as part of emergency services such as EAS notifications. Other types of messaging within a cable or satellite system may include service provider-to-user or user-to-user messaging. However, current services typically perform these messaging functions independent of one another. As a result, resources such as processing power, bandwidth, and software development time and cost may be unnecessarily expended if multiple services are performing essentially the same messaging functions in parallel over the same television system.
Therefore, an unsatisfied need exists in the industry for more efficient utilization of resources in development and implementation of messaging in cable and satellite systems.